Elastic exercise device

ABSTRACT

An elastic exercise device is provided, which is made of an expanded elastomer that has the strength and elasticity suitable for performing tension-type exercises. The device preferably consists of a single elongated piece or of an endless loop of desired size and shape. The device can have various cross-sectional profiles, such as a fully filled cylindrical configuration, a tubular configuration, an oval or flat band configuration or a multistrand configuration. The device can be made from elastomer materials such as neoprene or polyethylene by extrusion, casting or injection molding.

FIELD OF THE INVENTION

This invention relates to an elastic exercise device. In particular, it relates to a tension-type exercise device, such as a cord, band, tube or loop, made of an expanded elastomer material.

BACKGROUND OF THE INVENTION

Many elastic exercise devices, such as bands, cords, tubes, loops and the like, have been disclosed in the past. Examples of such devices may be seen from U.S. Pat. Nos. 1,663,641; 2,224,103; 3,655,185; 3,807,730; 3,819,177; 3,838,852; 4,019,734; 4,033,580; 4,040,620; 4,059,265; 4,090,706; 4,195,835; 4,121,827; 4,251,071; 4,852,874; 5,614,300; 5,945,060 and 6,287,242. All such exercise devices are made of rubber or similar solid elastomers, and most of them require handles or similar attachments to facilitate their use.

Due to the type of material used, namely a solid elastomer, the resilient member of the device must be thin enough to provide adequate stretchability in order to perform tension-type exercises. Such resilient members are hard to the touch and essentially not compressible when squeezed by hand during the exercises. This makes such devices uncomfortable for a hand grip, and hence the provision of handles or other features to provide a more hand grippable surface. Also, such devices are even less comfortable in contact with various parts of the exerciser's body when performing different types of workouts.

Another well recognized drawback of presently known elastic exercise devices is that when they are grasped at their ends, either by means of handles or by wrapping them around the fingers and then pulled by the exerciser, the tension progressively increases with the stretching rather than being constant throughout the exercise routine. This produces an uneven result when exercising the various muscles of the body.

Another disadvantage of the presently known and used elastic exercise devices made from solid elastomers, such as rubber or thermoplastic materials, is that they snap-back if suddenly released after stretching. This back-snapping property of such devices is very inconvenient and even dangerous if by accident the device is released when fully stretched.

For the above reasons, despite their considerable number and variety, known elastic exercise devices have not achieved a widespread use, particularly in home environments. There is thus a need for a simple, inexpensive and versatile elastic exercise device well adapted for personal use not only in fitness clubs, but also at home, in a hotel room or anywhere else.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide an elastic exercise device that will obviate or greatly reduce the disadvantages of known exercise devices described above.

Another object of this invention is to produce a simple, safe and multi-functional elastic exercise device, made of a single component which could readily be used anywhere by anyone.

Other objects and advantages of the invention will be apparent from the following description thereof.

In essence, the present invention provides an elastic exercise device comprising a stretchable resilient member essentially consisting of an expanded elastomer having size, shape, strength and elasticity suitable for performing tension-type exercises.

The exercise device of the present invention is normally a single component device that may have an elongated open-ended structure with round or a flattened cross-section, or a tubular structure or a cord like structure with multi-strand configuration or any other structure that is easy to grasp and hold by hand, which is made of an expandable elastomer having desired properties. The various above mentioned structures may be formed as a loop by connecting their ends to one another. Although the exercise device of the present invention does not require the addition of a handle or other attachments, such additional attachments may be used therewith if for some reason they are desired, for example as wall or door mountings.

The term “expanded” as used herein in conjunction with “elastomer” is also interchangeably referred to in the elastomer industry as “foamed”, “cellular” and/or “sponge”. In order to be expanded, the elastomer must be expandable by proper treatment. There are open cell and closed cell expanded elastomers and both are suitable for the purpose of the present invention. Open cell expanded elastomers have interconnecting cells produced by expansion of gases from chemical reactions when manufacturing such elastomers. Closed cell type expanded elastomers have non-interconnecting cells produced by controlled release of inert gases during the curing process; these gases are permanently entrapped as a multiplicity of separate bubbles in the elastomer matrix. The closed cell expanded elastomers are preferred for making the exercise device of this invention because, due to their closed cell configuration, they preclude moisture or body fluid absorption and therefore are more hygienic. If, however, open cell elastomers are used for economic or availability reasons, it is preferable to coat them with a thin elastic polymer skin or surface coating to provide a moisture impervious barrier.

A partial list of elastomers that may be expanded to form an expanded elastomer for the purposes of the present invention is as follows:

Neoprene Rubber (Chloroprene)

SBR Rubber (Styrene Butadiene)

Nitrile Rubber (Butadiene Acrylonitrile)

EPDM (Ethylene Propylene)

Viton (Fluorinated Hydrocarbon)

Natural Rubber (Natural Polyisoprene)

Fluorosilicone (Fluoro-Vinyl Silane)

Hypalon (Chlorosulfonated Polyethylene)

Silicone Rubber (Polysiloxane)

EVA (Ethylene-vinyl acetate)

Polyurethane (Polyester or Polyether Urethane)

PVC (Polyvinyl Chloride) based and non-PVC based plastisols

A practical and most cost effective manner of manufacturing the resilient member which forms or is an essential part of the exercise device of the present invention is by extrusion. A longitudinal closed cell elastomer shape may be produced by extruding the raw compound through a die orifice, which determines the cross-section of the extruded product. Then, the extruded stock is carried from the die orifice by a conveyor system in a continuous manner through vulcanizing chambers where heat causes the blowing agent to decompose and produce an inert gas which expands the extruded stock. This is followed by a continuous curing operation until vulcanization is complete. On emerging from the vulcanization chamber, the extrusion product is cooled to stabilize it dimensionally and in subsequent operations, the product is cut to predetermined lengths and if a loop is desired, its ends may be spliced to produce an endless loop. It should be noted that the process may be controlled to produce a desired volumetric expansion which may be anywhere from 100% to 1000%, typically an expansion/solid ratio of between 2 and 10. The elastomer must, however, be selected in conjunction with the expansion so as to produce adequate strength and elasticity of the product having an appropriate size and shape for the exercise function. These properties are determined by the tensile strength of the product which should normally be between about 75 psi and 500 psi (5 kg/cm²-35 kg/cm²) and its elongation to break which should be between about 100% and 600%. The preferred range for the tensile strength is between 100 psi and 400 psi (7 kg/cm²-28 kg/cm²) and for the elongation to break it is between 200% and 400%. Under these conditions, the specific weight of the device will normally be between about 10 lbs/ft³ and 25 lbs/ft³, corresponding to a density of between about 0.15 and 0.40.

The highly favorable characteristics of closed cell elastomers include (a) a direct formation of a natural skin that is clean and smooth, (b) the possibility of producing a continuous product of a desired diameter or shape that may be cut to desired lengths, and (c) the ability to produce hollowed or tubular profiles.

If a highly durable skin is desired for the extruded product, particularly with open cell elastomers, or for strenuous exercise or tear and wear, especially when in contact with attachments, a secondary vulcanization may be performed to form a thin, uniform, solid coating from the same or another polymer. Alternatively, an additional protective layer may be applied by liquid coating using known techniques, such as brushing, spraying or dip-coating. Such protective skin material should be more flexible and stretchable than the elastic exercise device on which it is applied and should have good adhesion to the substrate of such device and a good resistance to nicking and abrasion.

Moreover, the chosen coating may be pigmented to provide a desired coloring on the outside surface of the device. Some expanded elastomers are available only in one color, and they may be coated with a layer having any desired color. For example, neoprene is available only in black and, if desired, it can be coated with highly elastic colored polyurethane. Logos or other ornamentation may also be provided on the surface of the exercise device to make it more decorative or attractive. Moreover, graphic illustrations may be added which would be deformed during stretching to give a visual indication of the force level attained by the exerciser.

An alternative manufacturing process for making an exercise device in accordance with this invention is to cast the expanded elastomer in a molding die or to injection mold it. Casting or injection molding of this product would require a separate and fairly costly casting or molding die set for every size and sectional profile of the product. Also, hollowed or tubular profiles cannot be made in this manner. On the other hand, certain types of expandable elastomer, such as plastisols, cannot be easily extruded and therefore expanded plastisols are most conveniently made by casting or injection molding in multi-component dies. A further benefit of casting and injection molding is the elimination of splicing when making an endless exercise loop.

One of the preferred materials to produce the exercise device of the present invention is expanded neoprene rubber. Neoprene is the generic name for polychloroprene synthetic elastomers. It is readily available, moderately priced and non-allergenic. It is one of the best all-purpose elastomers with resistance to ozone, sunlight and oxidation. Added advantages are resistance to water, sun tanning oil and many chemicals. It also has good elasticity and tensile strength as well as is resistant to tear and repeated bendings.

Another very good material is expanded polyurethane. The benefits of making the exercise device from polyurethane include increased tensile strength over neoprene and better resistance to surface damage such as nicking. Also, polyurethane can be formulated in any desired color coding for differentiating multiple grades of tensile, strengths and providing greater appeal to stylish users. However, the expanded polyurethane extrusions are more expensive than those of neoprene.

The length and shape or cross-sectional profile of the novel exercise device may vary depending on who will use it. For women and youngsters, the device will usually be 0.75 inch to 1 inch (1.9 cm-2.5 cm) in diameter when it is of circular shape or its equivalent profile area with a different geometric shape. For a male user, it will normally be between 1 inch and 1¼ inches (2.5 cm-3.2 cm) in diameter or equivalent profile area. And for a well conditioned athlete, it may be as high as 1½ inches (3.8 cm) in diameter or equivalent profile area. One very good dimension is a tubular construction of 1¼ inches (3.2 cm) outer diameter with 0.5 inch (1.2 cm) hollow core. Thus, the overall cross-sectional profile area will normally vary between about 0.45 in² and 1.75 in² (2.9 cm²-11.3 cm²).

The length of the exercise device in either looped or open-ended configuration can vary from about 3 to 10 feet (0.9-3 m) with the most practical length being between about 7 and 8 feet (2.1-2.4 m).

As already mentioned above, the novel exercise device or its elastic member if other elements or features are used with it is characterized in that it essentially consists of a suitable expanded elastomer. The expression “essentially consists of” is used to mean that the expanded elastomer provides the required condition for the device to be used as a tension-type physical exerciser, however, it may contain some other features, such as an additional coating or coloring or the like to improve its properties or appearance.

It should be noted that the use of an expanded elastomer for performing tension-type exercises is both novel and surprising because such materials have until now been used only for compression-type applications, such as cushions, paddings, sponges, and the like. The applicant has found no known application of such materials where they would be used in tension-type application, let alone as an elastic exercise device. For this reason, technical data and characterization of properties of expanded elastomers for use under tension were not available from the prior art and had to be devised by the applicant for the purposes of this invention.

Thus, the applicant discovered that in order to make an exercise device with an expanded elastomer that has satisfactory strength and elasticity, a substantially increased cross-sectional area over known such devices is needed, generally between about 0.75 and 1.5 inches (1.9 cm-3.8 cm) in diameter for a circular profile or equivalent area if a different shape is used, which represents a cross-sectional area of between about 0.45 in² and 1.75 in² (2.9 cm²-11.3 cm²). It was also found that such increased size in the profile of the device is ideal to achieve a good ergonomic hand grip. Because of its expanded condition, the device is somewhat compressible when grasped by hand and assures a secure, cushioned and comfortable hold anywhere over its entire length. Also, by slightly releasing the grip, the user can slide his/her hand on the surface of the device, thereby controlling the tension as the device is stretched, making the load as even as possible over the movement range. To applicant's knowledge this cannot be achieved with any presently known elastic exercise device.

Further properties that favorably affect the device of the present invention were also found as a result of applicant's investigation into the use of expanded elastomers in tension. Thus, an exercise device made from an expanded elastomer stretches farther than an equal weight solid elastomer cord or band, when both are subjected to identical tensions. In this regard, it was found that an expanded elastomer, when used in tension, not only elongates in a linear molecular orientation, but additional stretching is generated by the geometric deformation of its cell structure. A microscopic examination showed that in a stretched expanded elastomer, the spherical forms of its cell matrix flatten into elliptical configuration as the normal polymeric elongation (also know as molecular orientation) of the solid portion of the elastomer also takes place. The resulting simultaneous interaction of these two elongations produces a significantly longer extension range than in an equivalent weight solid elastomer material. The applicant also found that this dual simultaneous stretching lasts only on approximately the first 200% of elongation and after this highly elastic zone is exceeded, only the polymeric deformation progresses further as in the solid elastomers. This property is quite useful for the purposes of the present invention, since the exercise workout range with elastic devices almost never exceeds the 200% stretch limit and thus, with the expanded elastomer, fully uses the enhanced elongation ability of the device.

Another surprising and useful property of expanded elastomer is that it exhibits a dampened retraction after being released suddenly from a stretched condition. Thus, the stretched expanded elastomer exercise device will not snap-back when suddenly released, as this occurs with known solid elastomer devices, but will retract in a dampened fashion which is much less dangerous for the user. Although the applicant does not wish to be restricted by the explanation of this dampening effect, it is believed to result from several causes. One of them is believed to be the elastomer's polymeric memory stabilization in the form of geometric restitution due to the retraction of the stretched molecules to their resting position. The other cause for the dampening effect is believed to result from cellular air/gas chamber cushioning, because the closed cell structure of expanded elastomers is composed of a multitude of air or gas bubbles which are compressible and which respond to the sudden contraction with a kind of shock absorption. Also, some air/gas diffusion through the microscopic porosity of the surface membrane of the elastic device during stretching and subsequent rapid retraction is also believed to contribute to the recoil dampening. This dampening phenomenon is very useful since it essentially eliminates potential injuries due to accidental release of the device, called back-snapping, which sometimes happens during workouts.

Interestingly, all these properties of the exercise device of the present invention are believed to also make it ideal for exercising under weightless environment, for example in space, performing the mandatory exercises prescribed by the NASA's Crew Health Care System on the International Space Station. Applicant has tested the device under water, simulating weightless conditions and found it very satisfactory. Moreover, applicant consulted a specialist at the University of Montreal doing research work on space exercising requirements and found that this exercise device will likely meet all required conditions for use in space.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of the simplest embodiment of the elastic exercise device in accordance with this invention, namely a single longitudinal piece made of an expanded elastomer;

FIG. 2 is a side view of another embodiment of the invention where the exercise device is in the form of a loop;

FIG. 3 illustrates the use of the device in accordance to the present invention, while maintaining substantially constant tension;

FIG. 4 is a cross-sectional view of one profile of the exercise device according to the invention, which has a fully filled tubular configuration;

FIG. 5 is a cross-sectional view of another profile of the exercise device according to the invention, which has a tubular configuration;

FIG. 6 is a cross-sectional view of a further profile of the exercise device according to the invention, which has a cord-like multi-strand configuration;

FIG. 7 is a cross-sectional view of a still further profile of the exercise device according to the invention, which has a generally oval configuration; and

FIG. 8 is a cross-sectional view of still another profile of the exercise device according to the invention which has a wider band configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The exercise device 10 shown in FIG. 1 represents the simplest form of applicant's invention.

It is a single longitudinal resilient piece made of an expanded elastomer that may have any desired cross-sectional configuration, provided it can be comfortably grasped by user's hands. Because it is used as a tension-type exercise device, for example, as illustrated in FIG. 3, it must possess adequate strength and elasticity for this purpose. This exercise device is also very convenient because it can be rolled into a compact package that may be taken anywhere by the user. It is, therefore, eminently portable. Although this simplest form of applicant's exercise device does not require any attachments, it is obvious that attachments may be affixed to it, if desired.

The endless loop 12 shown in FIG. 2 represents another embodiment of the present invention which the applicant considers to be the most preferred configuration of the exercise device. It may be produced from the elongated piece such as shown in FIG. 1, by solidly connecting the two ends of such piece at the joint 14. This joint 14 may be mechanical, but preferably it is made by cold vulcanization of the two ends, making sure that the tensile strength of the joint 14 is higher than that of the expanded elastomer, and preferably at least twice that of the expanded elastomer.

The endless loop exercise device is considered preferable to the open-ended version because it is more functional. Several hundred exercise routines can be performed with it, such as muscle toning, aerobics, stretching and physiotherapy and, in addition, it can be used in recreational exercises such as hula dancing and buoyancy assisted swimming. Moreover, it can be connected to a door frame supported pull-up bar or other types of wall-mounted implements without providing it with any attachments or the like.

FIG. 3 illustrates a squat exercise performed with the exercise device 10. As shown by arrows 16 and 18, the hand 20 of the exerciser can be slipped from a lower position to a higher as the load increases due to the stretching of the device 10, thereby maintaining an essentially equal tension during the exercise and allowing the exerciser to finish the movement throughout its full range of the workout motion.

FIG. 4 illustrates the basic cross-section of the exercise device 10 or 12 shown in FIG. 1 and FIG. 2 respectively. It has a circular configuration which is fully filled with a cellular expanded elastomer material 11.

FIG. 5 illustrates a tubular or cored cross-sectional profile that may be used in accordance with this invention. Here, the cellular elastomer 11 surrounds a hollow core 13 to form a tubular configuration. The outer diameter of the tube is typically between about 0.75 to 1.5 inches (1.9-3.8 cm) and the hollow core diameter is typically between about 0.25 to 0.5 inches (0.6 and 1.9 cm). Such cored design has the advantage of an increased overall cross-sectional dimension, while maintaining essentially the same amount of the expanded elastomer material as in FIG. 4. Moreover, the hollow core allows the device to flatten out more readily and on a wider area, providing more comfort when the device is being pushed against the user's body. The size of the core 13 may vary to suit a desired optimal configuration of the device. It should be noted also that although the device illustrated in FIG. 5 shows a tubular construction with only one core, it is also possible to have multiple cores in such tubular devices. For example, a triple cored extrusion can readily be made to provide a firmer tubular design. Thus, when reference is made herein to a tubular construction or cross-sectional profile, it includes designs with one or several cores.

FIG. 6 illustrates a multi-strand exercise device that may be used pursuant to the invention. Although this figure shows a configuration of six strands 22 wound around a central strand 24, it should be noted that two or more of such strands may be twisted or banded together to form a cord that is easy and comfortable to grasp and hold in a hand and which gives a more secure grip than a smooth surface of a cylindrical device shown in FIG. 4 or tubular device shown in FIG. 5. The size of the strands of the multi-strand device is normally adjusted to provide a comfortable hand grip as in the other configurations. It should be noted, however, that production of the multi-strand devices is more costly and such devices would be more expensive than the devices of FIG. 4 and FIG. 5, since they cannot be made by direct extrusion, casting or injection molding.

FIG. 7 and FIG. 8 illustrate further types of exercise devices which may be provided in accordance with this invention. These are band or ribbon type devices made of the expanded elastomer material 11, but providing more of a flat surface which is more comfortable when in contact with body parts of the user. Such devices are particularly useful for rehabilitation purposes. Due to the expanded elastomer characteristics, the pliable device of FIG. 8 can be readily crumpled by hand to maintain good control during the exercise.

The following non-limitative examples are provided by way of best mode realization of the present invention.

EXAMPLE 1

A 1 inch (2.5 cm) in diameter expanded neoprene extrusion was produced having the following properties:

Tensile strength: 146 psi (10.3 kg/cm²)

Elongation to break: 260%

Specific weight: 12 lbs/ft³ (Density: 0.19)

Volumetric expansion/solid ratio: 6.5

This extrusion was cut at a length of 7 ft (2.10 m) and spliced by its ends to form a loop. The splicing was done by cold vulcanization.

The obtained loop was extensively used as an exercise device performing a number of workout routines. The exercise device proved to be very satisfactory and durable.

EXAMPLE 2

A 1¼ inch (3.2 cm) in diameter expanded polyurethane casting was made which was 8 feet (2.4 m) long. The so produced piece had the following properties:

Tensile strength: 210 psi (14.7 kg/cm²)

Elongation to break: 370%

Specific weight: 17 lbs/ft³ (Density: 0.27)

Volumetric expansion/solid ratio: 4.4

This cast piece was tested extensively as an exercise device, giving excellent performance for a wide variety of workout routines.

It should be understood that the invention is not limited to the specific embodiments described and illustrated herein, but that various modifications obvious to those skilled in the art may be made without departing from the invention and the scope of the following claims. 

1. An exercise device comprising a stretchable resilient member essentially consisting of an expanded elastomer, having size, shape, strength and elasticity suitable for performing tension-type exercises.
 2. An exercise device according to claim 1, consisting of a single stretchable resilient member made of the expanded elastomer.
 3. An exercise device according to claim 2, in which said single stretchable resilient member is an elongated open-ended piece having a length between 3 and 10 feet (0.9 m-3 m).
 4. An exercise device according to claim 2, in which said single stretchable resilient member is in the form of a closed loop.
 5. An exercise device according to claim 1, in which said expanded elastomer is expanded neoprene.
 6. An exercise device according to claim 1, in which said expanded elastomer is expanded polyurethane.
 7. An exercise device according to claim 1, in which said expanded elastomer is selected from the group consisting of natural rubber, styrene-butadiene rubber, nitride rubber, silicone rubber, ethylene-propylene polymer, fluorinated hydrocarbon polymer, fluorosilicone polymer, chlorosulfonated polyethylene polymer, ethylene-vinyl acetate polymer and a plastisol.
 8. An exercise device according to claim 1, in which said expanded elastomer is an open cell expanded elastomer.
 9. An exercise device according to claim 1, in which said expanded elastomer is a closed cell expanded elastomer.
 10. An exercise device according to claim 1, in which said expanded elastomer has a volumetric expansion to solid ratio (expansion/solid) of between about 2 and
 10. 11. An exercise device according to claim 1, in which said expanded elastomer has a tensile strength of between about 100 psi and 500 psi (7 kg/cm²-35 kg/cm²)
 12. An exercise device according to claim 1, in which said expanded elastomer has an elongation to break of between about 100% and 600%.
 13. An exercise device according to claim 1, in which said expanded elastomer has a specific weight of between about 10 lbs/ft³ and 25 lbs/ft³ corresponding to a density of between about 0.15-0.40.
 14. An exercise device according to claim 1, in which the stretchable resilient member is formed by extrusion.
 15. An exercise device according to claim 1, in which the stretchable resilient member is formed by casting.
 16. An exercise device according to claim 1, in which the stretchable resilient member is formed by injection molding.
 17. An exercise device according to claim 1, in which the stretchable resilient member has the shape of an elongated cylindrical piece with a circular cross-section having a diameter of between about 0.75 inch and 1.5 inch (1.9 cm-3.8 cm).
 18. An exercise device according to claim 1, in which the stretchable resilient member has the shape of a tube with a hollow core in the middle, an outer diameter of between about 0.75 inch and 1.5 inches (1.9 cm-3.8 cm) and the hollow core diameter of between about 0.25 and 0.5 inch (0.6 cm-1.2 cm).
 19. An exercise device according to claim 1, in which the stretchable resilient member has the shape of a multi-strand cord.
 20. An exercise device according to claim 1, in which the stretchable resilient member has the shape of an oval or flat band.
 21. An exercise device comprising a stretchable resilient member made of an expanded elastomer having a volumetric expansion to solid ratio of between about 2 and 8, a density of between about 0.15 and 0.40, a tensile strength of between about 100 psi and 500 psi (7 kg/cm²-35 kg/cm²) and an elongation to break of between about 100% and 600%, said stretchable resilient member having a length of between about 3 ft and 10 ft (0.9 m-3 m) and a cross-sectional area of between about 0.45 in² and 1.75 in² (2.9 cm²-11.3 cm²). 